A variety of reasons. De-skilling of work, for instance, which leaves skilled people doing the same simple work for the same low wages as the unskilled. Lack of opportunities to learn new skiills. The zero-hours contract which basically leaves one sitting by the phone waiting for a call. Before that, if you only had a part-time job, you were working fixed hours and knew what time you had available to take another one. Now, you never know when your boss will want you in, so you're stuck with the one job. The general paucity of work. The fact that looking for a new job will, in 75% of cases, get you instantly fired from the one you have. Also, there are few chances of promotion for an Uber driver or Deliveroo rider.

People forget that until 1945 or so, working-class people lived hand to mouth. The decades since have been a blip, and now we are returning to the 'norm' which has existed since the Bronze Age. The end of the Cold War and the collapse of Communism means that the working classes no longer need to be coddled by their masters.